Diamond dresser arm assembly



Sept. 28, 1965 o, R. BRINEY, JR

DIAMOND DRESSER ARM ASSEMBLY 2 Sheets-Sheet 1 Filed Oct. 22, 1962 mw..,N Tm x mn n vB 7 mk, A .w .n O

Sept. 28, 1965 o. R. BRINEY, JR

DIAMOND DRESSER ARM ASSEMBLY 2 Sheets-Sheet 2 Filed Oct. 22, 1962 meg.=. INVENTOR.

O-rrgs RYyBR/NEY J'R.

United States Patent O 3,208,445 DIAMOND DRESSER ARM ASSEMBLY Gttis R.Briney, '.Ir., Pontiac, Mich., assignor to Briney Manufacturing Co.,Pontiac, Mich., a corporation of Michigan Filed Oct. 22, 1962, Ser. No.232,163 16 Claims. (Cl. y'12S-11) The invention relates to materialforming apparatus and refers more specically to a dresser arm assemblyfor use in diamond dressing a grinding Wheel or the like including asingle or plurality of tool carrying heads adjustable from the endthereof opposite dressing tools carried thereby without being locked andunlocked.

In the past adjustment of individual tools carried by a dresser armassembly has been a relatively tedious and inecient task since withprior adjusting means locking and unlocking of each of the individualtool carrying heads thereof has been necessary in adjusting eachindividual tool. Locking and unlocking of the individual tool carryingheads is particularly undesirable since after an adjustment relocking ofa tool carrying head often produces a substantial change in adjustment.In addition with prior constructions adjustment of the individual toolcarrying heads has been accomplished from the end of the heads fromwhich the tools extend which is undesirable since very little room isusually available at this end of the heads in the usual dresser armassembly and installation.

It is therefore one ofthe objects ofthe present invention to provide animproved dresser arm assembly for use in dressing of grinding wheels andthe like.

Another object is to provide an improved dresser arm assembly includinga supporting frame having secured thereto a plurality of tool carryingheads adjustable from the ends thereof opposite that from which toolscarried thereby extend.

Another object is to provide a dresser arm assembly as set forth abovewherein the individual tool carrying heads are separately adjustablelongitudinally of the arm assembly.

Another object is to provide a dresser arm assembly as set forth abovewherein each of the tool carrying heads includes a substantiallyrectangular body member having a cylindrical opening therethrough, aneccentric cylindrical sleeve positioned within the opening having aradially outwardly extending ange at one end thereof engageable with thebody member around one end of the opening to prevent passage of thesleeve through the opening, a bar holder extending through the sleevehaving a radially extending flange on one end thereof engaged with theflange on the eccentric sleeve, an adjusting member positioned withinthe -other end of the opening through the body member having a radiallyextending flange therearound operable to prevent the adjusting memberfrom passing through the opening in the body member, resilient meansextending between the adjusting member and bar holder to hold the barholder, eccentric sleeve and adjusting member in assembly in the openingin the body member, means to prevent relative rotation between the barholder yand body member and means to provide rotation of said eccentricsleeve with said adjusting member.

Another object is to provide a tool carrying head including means foradjustably supporting a tool at one end thereof and means for adjustingthe position of the tool carried at said one end thereof relative to anaxis therethrough secured to the other end thereof.

Another object is to provide a tool carrying head including a bodymember having a cylindrical opening therethrough, an eccentric sleevepositioned within the cylindrical opening having a radially outwardlyextending ilange at one end thereof operable to prevent the sleeve frompassing through the opening, a bar holder positioned within theeccentric sleeve having a radially outwardly extending flange thereonengageable with the flange on the eccentric sleeve to prevent passage ofthe bar holder through the opening, a tool bar secured to the barholder, an adjusting member positioned in the other end of the openingthrough the body member having a radially outwardly extending flangethereon for preventing passage of the adjusting member through theopening, resilient means operable between the adjusting member and barholder for securing the adjusting member, bar holder and sleeve withinthe opening in the body member, a plurality of pre-stressed balls incylindrical cages positioned between the bar holder and inner surface ofthe eccentric sleeve and between the outer surface of the eccentricsleeve and body member, means to prevent -relative rotation between thebody member and bar holder and for securing the adjusting member andeccentric sleeve together for simultaneous rotation.

Another object is to provide a dresser arm assembly which is simple inconstruction, economical to manufacture and elicient in use.

Other objects and features of the invention will become apparent as thedescription proceeds, especially when taken in conjunction with theaccompanying drawings, illustrating a preferred embodiment of theinvention, wherein:

FIGURE 1 is an elevation view of a dresser arm assembly constructed inaccordance with the invention.

FIGURE 2 is a view of the dresser arm assembly illustrated in FIGURE 1taken in the direction of the arrow 2 in FIGURE 1.

FIGURE 3 is a partial end view of the dresser arm assembly illustratedin FIGURE 1 taken in the direction of arrow 3 in FIGURE 1.

FIGURE 4 is an enlarged section view of the dresser` larm illustrated inFIGURE 1 taken on the line 4f4 in FIGURE l.

FIGURE 5 is a partial section view of the dresser arm illustrated inFIGURE l taken substantially on line 5-5 in FIGURE 4.

FIGURE 6 is a partial section view of the dresser arm illustrated inFIGURE 1 taken on line 6 6 in FIG- URE 4.

With particular reference to the figures of the drawings one embodimentof the invention Will now be considered in detail.

As shown best in FIGURE l the dresser arm 10 comprises an elongatedsupporting frame 12 to which'a plurality of tool carrying headassemblies 14 are adjustably secured. The supporting frame 12, as shownin FIGURE l, is pivotally mounted for arcuate movement in the `directionof arrow 16 whereby the tools 20 may be moved into and out of dressingposition with respect t-o the .grinding wheel 22 to be dressed thereby.

The tool carrying head assemblies 14 are constructed so that the toolbars 24 may be adjusted transversely of the dresser arm assembly fromthe end 26 of the tool carrying head assemblies opposite the tool bars24. In addition the tool carrying head assemblies are so constructedthat it is not necessary to lock Ior unlock the assemblies before orafter adjustment of the position of the tool bars has been accomplished.Adjustment of the tool bars is thus facilitated with the dresser armassembly of the invention.

More specically the supporting frame 12 includes a pair of elongatedilat rectangular side plates 28 .and 30 held in parallel spaced apartrelation by spacing blocks 32 and 34 which spacing yblocks are secured-between the ends 36 and 38 of the side plates 28 .and 30 by convenientmeans, such as welding or bolts.

As shown best in FIGURE 1 the sub-assembly consisting .of the sideplates 28 and 30 and spacing blocks 32 and 34 are secured t-o asupporting bracket 40 by means of bolts 42 extending through theopenings 44 and 46 in the spacing block 32 and supporting bracket 40,respectively. An additional spacing block 48, as shown in FIGURE 1, maybe provided between the supporting bracket 40 and spacing block 32 ifdesired. Bracket 40 is pivotally mounted to permit swinging of thesupporting frame 12 in the direction or arrow 16 by convenient pivotalsupport means (not shown).

The tool carrying head assemblies 14, as shown best in FIGURE 4, eachinclude a generally rectangular body member 50, e-ccentric sleeve 52,bar holder 54 and bearing structures 56 and 58 separating the bodymember from the eccentric sleeve and the eccentric sleeve from the barholder, respectively. The tool carrying head assemblies 14 are completedby the adjusting member 60 and the resilient means 62 acting between thebar holder 54 and adjusting member 60 to secure the body member,eccentric sleeve, bar lholder and adjusting member in assembly.

Body member 50, as illustrated best in FIGURE 4 is generally rectangularand is provided with offset sides 64 to produce the abutments 66 wherebythe body member fits between the side plates 218 and 30 of thesupporting frame 12 and is supported for sliding movement on thesurfaces 68 and 70 of the side plates.

Body member 50 of the head assemblies 14 is further provided withthreaded openings 72 in the sides thereof for receiving bolts 74 thereinwhich are operable to secure the head assemblies 14 in 4a longitudinallyadjusted position on the supporting frame 12. Longitudinal adjustment ofthe tool carrying head assemblies 14 may be accomplished due to theelongated slots 76 provided in the side plates 28 and 30 through whichthe bolts 74 having washers 78 sleeved thereover extend.

Body member 50 is further provided with a cylindrical opening 80extending therethrough, as shown best in FIGURE 4, in which theeccentric sleeve 52, bar holder 54 land bearing structures 56 and 58 arereceived. The longitudinally extending notch 82 provided in the end 84of the opening 80 cooperates with the tongue portion 86 of the drivingplate 88 to prevent relative rotation between the bar holder 54 and thebody member 50, as Will be considered in more detail subsequently.

Eccentric sleeve 52 is provided with the radially outwardly extendingange 90 at the end 92 thereof including the beveled `abutment 94 thereonengageable with the mating beveled surface 96 at the end 98 of theopening 80 through the body member 50 to position the eccentric sleeve52 axially within the opening .80. lEccentric sleeve 52 is provided withthe longitudinally extending slot 100 therein in which the tongueportion 102 of the adjusting member `60 is positioned whereby rotationof the adjusting member 60 produces a similar rotation of the eccentricsleeve 52.

The eccentricity of the sleeve 52 is provided between the radially innerand outer cylindrical surfaces thereof. Thus on rotation of theeccentric sleeve S2 relative to the body member 50 and bar holder 54movement of the bar holder 54 in the direction of arrow 104 in FIGURE 2is accomplished to produce adjustment of dressing tool 20, as will beconsidered in more detail subsequently.

Bar holder 54 again, .as shown best in FIGURE 4, comprises a solidcylindrical member 106 having a radially extending flange 108 at end 110there-of and the beveled surface 112 thereon engaged With the beveledsurface 114 on the sleeve 52 for axially positioning the bar holder 54with respect to the eccentric sleeve 52. Drive plate 8S is secured tothe end 116 of bar holder 54 by convenient means, such as the tongue 118on the drive plate -88 and groove 120 in the bar holder 54 and bolts 122extending through the drive plate 88 on both sides of the axis ofgeneration of the cylindrical portion 106 4 of the bar holder and intothe cylindrical portion 106 of the bar holder. Thus it will be seen thatthe drive plate 88 is rigidly secured to the bar holder 54 whereby withthe tongue 86 of the bar holder 54 positioned in the notch 82 in thebody member 50 the bar holder 54 is prevented from rotation relative tothe body member.

The bea-ring assemblies 56 and 58 separating the body member 50 from thesleeve 52 and the sleeve 52 from the bar holder 54 each comprise acylindrical sleeve or cage 124 having a plurality of openings 126extending transversely therethrough in which the individual ballbearings 128 are held. The dimensions Iof the bearings, body member,sleeve and -bar holder are such that the bearings are under a slightcompressive force in assembly. Thus with the tool carrying headstructure illustrated in FIGURE 4 it is not necessary to lock and unlockthe adjusting member 60 between adjustments of the po'- sition of thetool bar 24 which is secured to the bar holder 54 for movement therewithon rotation of the eccentric sleeve with respect thereto.

As shown the tool bar 24 may be of different configuration depending onthe grinding wheel 22 or other structure to be dressed with the tools 20carried by the dresser arm assembly 10. Each of the tool bars 24 aresecured to a bar holder 54 by means of a tongue 130 and groove 132operable therebetween in cooperation with bolts 133. It will be notedthat the tongue and groove operable between the tool bar and bar holderof each of the tool carrying head assemblies 14 are positionedeccentrically with respect to the axis of the opening through the bodymember and the axis of generation of the sleeve 52 and the axis of thebar holder 54. Thus dressing forces applied through the tools 20 to thetool bar 24 and bar holder 54 have less tendency to cause undesirablereadjustment of the set position 0f a cutting tool 20 carried `by thetool bar 24.

Adjusting member 60 again, as shown best in FIGURE 4, is a cylindricalmember having an end portion 134 received Within the end 136 of theopening 80 in the body member 50, an end 138 extending beyond thesurface 140 `0f the body member 50 and a radially extending flange 142positioned centrally thereof and engageable with the surface 140 of thebody member 50. The outer periphery 144 of the flange 142 is calibrated,as illustrated best in FIGURE 3, and in conjunction with a calibration146 on the body member provides an indication of the amount ofadjustment of a tool 20 carried by a tool carrying head assembly 14 onrelative rotation of the adjusting member 60 with respect to the bodymember 50.

Adjustment of the adjusting member 60 is accomplished by means ofinserting an adjusting tool within the cylindrical openings 148extending at right angles through the end 138 0f the adjusting member 60and turning the adjusting tool to produce rotation of the adjustingmember. Adjustment of the position of the tool 20 may thus beaccomplished from the end of the tool carrying head assembly 14 oppositethe end thereof to which the tool 20 is secured, due to the rotation ofthe eccentric sleeve 52 with the adjusting member 60 in view of the slot100 and tongue 102 connection therebetween.

The adjusting member 60 is further provided with the axially extendingbore 150 having a large diameter portion 152 and a small diameterportion 154. The headed bolt 156 received in the large diameter portion152 of the bore 150 and extending through the small diameter portion 154thereof into a threaded opening 158 in the drive plate 88 and theresilient spring 160 operable between the bolt 156 and the adjustingmember 60 provide the resilient means operable to hold the bar holder,eccentric sleeve, body member and adjusting member in assembly.

In over-all operation, when it is desired t0 dress the grinding wheel22, the tool carrying head assemblies 14 which have previously beenlongitudinally positioned on the supporting frame 12 by means of thebolts 74 and elongated slots '76 .are adjusted transversely of thedresser arm assembly by rotating the adjusting members 60 on placing anadjusting tool in the cylindrical openings 148.

Rotation yof an adjusting member 60 will produce corresponding rotationof the eccentric sleeve 52 due to the slot and tongue connectiontherebetween. Since the bar holder 54 is prevented from rotationrelative to the body member 50 by the tongue 82. and notch 86 connectiontherebetween `and the body member is held in a fixed position on thesupporting frame 12 the bar holder 54 is caused to move transversely ofthe dresser arm assembly in the direction of arrow 104 due to therelative eccentricity between the inner and outer cylindrical surfacesof the sleeve 5,2.

The tool bar 54 and therefore the cutting tool 20 connected to the barholder 54 thus adjusted, are similarly adjusted to provide a desiredlocation of the dressing tool on pivoting of the dresser arm intodressing relation to the grinding wheel 22 `or `other device to bedressed. The dresser arm is then pivoted in a direction opposite thearrow 16 to move the dressing tool 20 into engagement with the structureto be dressed thereby.

Thus it will be seen that in accordance with the invention there isprovided an improved dresser arm assembly wherein dressing tools may be.adjusted without locking and unlocking the adjusting means therefor andwithout interference with the adjusting means by the dressing tools tobe adjusted or the structure to be dressed. While one embodiment of theinvention has been considered in detail, other embodiments andmodifications thereof are contemplated. It is therefore the intention toinclude all such embodiments and modifications as are defined by theappended claims within the scope of the invention.

What I claim as my invention is:

1. A dresser arm for use in dressing a grinding wheel or similarstructure comprising an elongated supporting frame, a plurality ofparallel extending tool carrying heads secured to the supporting framein longitudinally spaced relation therealong, each of which headsincludes a generally rectangular body member carried by the supportingframe and having a cylindrical opening therethrough, an eccentric sleevepositioned within the opening through the body member having a radiallyoutwardly extending flange at one end thereof engageable with the bodymember around the periphery of the opening therethrough at one endthereof for preventing passage of the sleeve completely through theopening, a cylindrical bar holder inserted within said sleeve having atool bar mounting flange extending radially outwardly at one end thereofengaged with the radially extending flange on the eccentric sleeve, atool bar secured to said bar holder at said one end thereof, acylindrical adjusting member inserted in the other end of the opening inthe body member having a radially outwardly extending flange thereonengageable with the body member to prevent passage of the adjustingmember through the opening in the body member, resilient means operablebetween the vbar holder and adjusting member for securing the barholder, eccentric sleeve and adjusting member within the opening in thebody member, means operable between the eccentric sleeve and adjustingmember for rotating the eccentric sleeve relative to the body member andbar holder in response to rotation of the adjusting member, and meansoperable between the bar holder and body member for preventing relativerotation between the bar holder and body member during rotation of saideccentric sleeve with respect thereto whereby the position of the toolbar may be adjusted with respect to the head on which it is mounted.

2. Structure as set forth in claim 1 wherein the means for preventingrelative rotation between the bar holder and body member comprises anaxially extending notch in the opening in the body member and a driveplate rigidly secured to the other end of the body member 6 having atongue portion positioned within the notch in the body member.

3. Structure as set forth in claim 2 wherein the resilient meanscomprises an opening through the adjusting member, a threaded recess inthe drive plate, a headed bolt passing through the opening in theadjusting member and secured in the threaded recess in the drive plateand a spring operable between the headed bolt and adjusting memberyurging the Iheaded bolt and adjusting member in opposite directions.

4. Structure as set forth in claim 1 wherein the means for rotating theeccentric sleeve relative to the body member comprises an axiallyextending slotin the other end of the eccentric sleeve and an axiallyextending tongue on the adjusting member extending into said slot.

5. Structure as set forth in claim 1 wherein the adjusting member isprovided with graduations around the radially extending flange and thebody member is provided with a corresponding graduation therein and theadjusting member further includes a projection thereon having aplurality of transverse openings therethrough for the insertion of atool therein for rotating the adjusting member.

6. An adjustable tool supporting head comprising a generally rectangularbody member having a cylindrical opening therethrough, an eccentricsleeve positioned within the opening through the body member having aradially outwardly extending flange at one end thereof engageable withthe body member around the periphery of the opening therethrough at oneend thereof for preventing passage of the sleeve completely through theopening, a cylindrical bar holder inserted within said sleeve having atool bar mounting flange extending radially outwardly at one end thereofengaged with the radially extending ange on the eccentric sleeve, a toolbar secured to said bar holder at said one end thereof, cylindricalcages having a plurality of ball bearings secured thereto insertedbetween the body member and sleeve and the sleeve and bar holder, acylindrical adjusting member inserted in the other end of the opening inthe body member having a radially outwardly extending flange thereonengageable with the body member to prevent passage of the adjustingmember through the opening in the body member, resilient means operablebetween the bar holder and adjusting member for securing the bar holder,eccentric sleeve and adjusting member within the opening in the bodymember, means operable between the eccentric sleeve and adjusting memberfor rotating the eccentric sleeve relative to the body member and barholder in response to rotation of the adjusting member and meansoperable between the bar holder and body member for preventing relativerotation between the bar holder and body member during rotation of saideccentric sleeve with respect thereto.

7. Structure as set forth in claim 6 wherein the means for preventingrelative rotation between the bar holder and body member comprises anaxially extending notch in the opening in the body member and a driveplate rigidly secured to the other end of the bar holder having a tongueportion positioned within the notch in the body member.

8. Structure as set forth in claim '7 wherein the resilient meanscomprises an opening through the adjusting member, a threaded recess inthe drive plate, a headed bolt passing through the opening in theadjusting member and secured in the threaded recess in the drive plateand a spring operable between the headed bolt and adjusting memberurging the headed bolt and adjusting member in opposite directions.

9. Structure as set forth in claim 6 wherein the means for rotating theeccentric sleeve relative to the body member and bar holder comprises anaxially extending slot in the other end of the eccentric sleeve and anaxially extending tongue on the adjusting member extending into saidslot.

10. Structure as set forth in claim 6 wherein the adjusting member isprovided with graduations around the radially extending flange and thebody member is provided with a corresponding graduation thereon and theadjusting member further includes a projection thereon having aplurality of transverse openings therethrough for the insertion of atool therein for rotating the adjusting member.

11. An adjustable tool supporting head comprising a body member having acylindrical opening therethrough, an eccentric sleeve positioned withinthe opening through the body member having means at one end thereof forpreventing passage of the sleeve completely through the opening, acylindrical bar holder inserted within said sleeve, a tool bar securedto one end of said bar holder, an adjusting member inserted in the otherend of the opening in the body member including means for preventingpassage thereof through the opening in the body member, resilient meansoperable between the bar holder and adjusting member for securing thebar holder, eccentric sleeve and adjusting member within the opening inthe body member, means operable between -the eccentric sleeve andadjusting member for rotating the eccentric sleeve relative to the bodymember and bar holder in response to rotation of the adjusting memberand means operable between the bar holder and body member for preventingrelative rotation between the bar holder and body member during rotationof said eccentric sleeve with respect thereto.

12. Structure as set forth in claim 11 wherein the means for preventingrelative rotation between the bar holder and body member comprises notchand tongue structure operable therebetween.

13. Structure as set forth in claim 11 wherein the resilient meanscomprises an opening through the adjusting member, a headed bolt passingthrough the opening in the adjusting member and secured to the barholder and a spring operable between the headed bolt and adjustingmember.

14. Structure as set forth in claim 11 wherein the means for rotatingthe eccentric sleeve relative to the body member and bar holdercomprises tongue and slot means operable between the adjusting memberand eccentric sleeve.

15. A dresser arm for use in dressing a grinding wheel or similarstructure comprising a supporting frame including a pair of elongatedparallel side members connected together at one end thereof and mountedfor pivotal movement about said one end, a plurality of separate toolcarrying heads secured to the supporting frame between said members inlongitudinally spaced relation at the other end thereof, each of whichheads includes a rectangular body member secured between the parallelside members having a cylindrical opening therethrough, an eccentricsleeve positioned within the opening through the body member havingmeans at one end thereof for preventing passage of the sleeve completelythrough the opening, a cylindrical bar holder inserted within saidsleeve including means for preventing passage of the bar holder to saidsleeve, a tool bar secured to said bar holder at one end thereof, anadjusting member inserted in the other end of the opening in the bodymember including means to prevent passage thereof through the opening inthe body member, resilient means operable between the bar holder andadjusting member for securing the bar holder, eccentric sleeve andadjusting member within the opening in the body member, means operablebetween the eccentric sleeve and adjusting member for rotating theeccentric sleeve relative to the body member and bar holder in responseto rotation of the adjusting member and means operable between the barholder and body member for preventing relative rotation between the barholder and body member during rotation of said eccentric sleeve withrespect thereto.

16. A dresser arm for use in dressing a grinding wheel or similarstructure comprising a supporting frame including a pair of elongatedparallel side members connected together at one end thereof and mountedfor pivotal movement about said one end, a plurality of separate toolcarrying heads secured to the supporting frame between said members inlongitudinally spaced relation at the other end thereof, each of whichheads includes a rectangular body member secured between the parallelside members having a cylindrical opening therethrough, an eccentricsleeve positioned within the opening through the body member havingmeans at one end thereof for preventing passage of the sleeve completelythrough the opening, a cylindrical bar holder inserted within saidsleeve including means for preventing passage of the bar holder to saidsleeve, a tool bar secured to said bar holder .at one end thereof, anadjusting member inserted in the other end of the opening in the bodymember including means to prevent passage thereof through the opening inthe body member, resilient means operable between the bar holder andadjusting member for securing the bar holder, eccentric sleeve andadjusting member within the opening in the body member, means operablebetween the eccentric sleeve and adjusting member for rotating theeccentric sleeve relative to the body member and bar holder in responseto rotation ofthe adjusting member and means operable between the barholder and body member for preventing relative rotation between the barholder and body member during rotation of said eccentric sleeve withrespect thereto and separate means for adjusting the individual toolcarrying heads longitudinally of the parallel side members.

References Cited by the Examiner UNITED STATES PATENTS 2,258,037 10/41Storz 51-58 2,275,327 3/ 42 Sheridan et al 29-97 2,375,926 5/45 Julian29-105 2,618,992 11/52 Charles 144-24 2,867,031 1/59 Briney et al.29-105 2,872,913 2/59 Rosier 12S-11.5 3,079,815 3/ 63 Briney et al7758.34

LESTER M. SWINGLE, Primary Examiner.

FRANK E. BAILEY, Examiner.

1. A DRESSER ARM FOR USE IN DRESSING A GRINDING WHEEL OR SIMILARSTRUCTURE COMPRISING AN ELONGATED SUPPORTING FRAME, A PLURALITY OFPARALLEL EXTENDING TOOL CARRYING HEADS SECURED TO THE SUPPORTING FRAMEIN LONGITUDINALLY SPACED RELATION THEREALONG, EACH OF WHICH HEADSINCLUDES A GENERALLY RECTANGULAR BODY MEMBER CARRIED BY THE SUPPORTINGFRAME AND HAVING A CYLINDRICAL OPENING THERETHROUGH, AN ECCENTRIC SLEEVEPOSITIONED WITHIN THE OPENING THROUGH THE BODY MEMBER HAVING A RADIALLYOUTWARDLY EXTENDING FLANGE AT ONE END THEREOF ENGAGHEABLE WITH THE BODYMEMBER AROUND THE PERIPHERY OF THE OPENING THERETHROUGH AT ONE ENDTHEREOF FOR PREVENTING PASSAGE OF THE SLEEVE COMPLETELY THROUGH THEOPENING, A CYLINDRICAL BAR HOLDER INSERTED WITHIN SAID SLEEVE HAVING ATOOL BAR MOUNTING FLANGE EXTENDING RADIALLY OUTWARDLY AT ONE END THEREOFENGAGED WITH THE RADIALLY EXTENDING FLANGE ON THE ECCENTRIC SLEEVE, ATOOL BAR SECURED TO SAID BAR HOLDER AT SAID ONE END THEREOF, ACYLINDRICAL ADJUSTING MEMBER INSERTED IN THE OTHER END OF THE OPENING INTHE BODY MEMBER HAVING A RADIALLY OUTWARDLY EXTENDING FLANGE THEREONENGAGEABLE WITH THE BODY MEMBER TO PREVENT PASSAGE OF THE ADJUSTINGMEMBER THROUGH THE OPENING IN THE BODY MEMBER, RESILIENT MEANS OPERABLEBETWEEN TGHE BAR HOLDER AND ADJUSTING MEMBER FOR SECURING THE BARHOLDER, ECCENTRIC SLEEVE AND ADJUSTING MEMBER WITHIN THE OPENING IN THEBODY MEMBER, MEANS OPERABLE BETWEEN THE ECCENTRIC SLEEVE AND ADJUSTINGMEMBER FOR ROTATING THE ECCENTRIC SLEEVE RELATIVE TO THE BODY MEMBER ANDBAR HOLDER IN RESPONSE TO ROTATION OF THE ADJUSTING MEMBER, AND MEANSOPERABLE BETWEEN THE BAR HOLDER AND BODY MEMBER FOR PREVENTING RELATIVEROTATION BETWEEN THE BAR HOLDER AND BODY MEMBER DURING ROTATION OF SAIDECCENTRIC SLEEVE WITH RESPECT THERETO WHEREBY THE POSITION OF THE TOOLBAR MAY BE ADJUSTED WITH RESPECT TO THE HEAD ON WHICH IT IS MOUNTED.